Cryptography and Image watermarking are filled with apparent oxymora and paradoxes. Random sequences are used as keys to encrypt information to be used as watermark during embedding the watermark and also to extract the watermark during detection. Therefore a deterministic random number sequence is very much useful for watermarking applications. In order to obtain the same random number sequence, we need to pass the same seed to the generator.
Many researchers have used DRNG for cryptographic applications and Pseudo Noise Random sequence (PN) for watermarking. Even though, there are some weaknesses in PN due to attacks, the research community used it mostly in digital watermarking. On the other hand, DRNG has not been widely used in watermarking due to its computational complexity and non-robustness. Therefore, we have invented a new design of generating DRNG using Pi-series to make it useful for Cryptographic and Digital watermarking applications.